Color television image reproduction



I SUBSTITUTE FOR MISSING COPY JJw-C'J RE 25 v 833 Aug. 10, 1965 H. C-GOODRICH COLOR TELEVISION IMAGE REPRODUCTION Orig. 2 3M3 Original FiledMarch 21 1951 I NVENTOR md'ltk O RNEY ERR ll beam as it scans the screenUnited States Patent poration of Delaware 0r nal No. 2,634,326 datedApr. 7, 1953, Ser. No. 2 6,766, Mar.2l, 19 Applicationforrelssue-Iam28,1955, Ser. No. 484,862

17 Claims. (Cl. 178-54) Nlatter enclosed in heavy brackets appears inthe original patent but forms no part of this reissue s ification;matter printed in italics indicates the additions made by reissue.

This invention relates to television image reproducing systems andparticularly, but not necessarily exclusively, to apparatus forcontrolling an electron beam so as to excite the luminescent screen of altinescope in a manner to reproduce television images substantially intheir natural co ors.

The invention is related in general to systems of the type employing amulticolor kinescope such as that disclosed in US. Patent 2,310,863,granted February 2, 1943 to H. W. Leverenz and entitled LuminescentScreen." The screen of such a tube consists of discrete phosphor stripsof a subelemental width and capable respectively of emittingdiil'erently colored light when excited by an electron beam. Thephosphor strips extend generally in a horizontal direction and theelectron beam is deflected over the screen generally in a conventionalmanner. difl'erent phosphor strips of each of the groups are selectivelyexcited to successive groups of strips horizontally. In order to[successively] successfully operate a tube of the [connection] characterdescribed, it is necessary that the vertical deflection of the beam beeffected with a high degree of linearity.

Accordingly, it is an object of the present invention to provide animproved color television reproducing system in which an electron beamis maintained in substantially exact registration with a line phosphorscreen.

Another object of the invention is to provide an electron beamcontrolling system in which signals generated in response to the beamdeflection over a line phosphor screen are employed to maintain adesired registration of the beam with the screen.

In accordance with the invention, the image reproducing kinescope isprovided with a line phosphor screen, the elements of which are capableof producing light of different colors when excited by an electron beam.The screen is also provided with signal generating facilities responsiveto excitation by the beam and indicative of the registration of the beamwith the screen. One of the features of the invention is in verticallydeflecting the horizontally so as to successively and repeatedlytraverse each of the phosphor strips comprising the group being scanned.The auxiliary vertical deflection of the beam may be efiected accordingto any predetermined pattern such as represented by a sine wave or asawtooth wave, for example.

According to the invention, the signals generated by the excitation ofthe screen by the electron beam are combined with a wave correspondingto the auxiliary deflection of the beam to produce signals that may beused to control the vertical deflection wave generator, by means ofwhich the beam is influenced to scan a conventional raster, so as toetfect the desired registration of the beam with the screen.

The novel features that are considered characteristic of this inventionare set forth with particularity in the appended claims. The inventionitself, however, both as to its organization and method of operation aswell as additional objects and advantages thereof will best beunderstood from the following description taken in connection with theaccompanying drawing.

The single figure of the accompanying drawing is a combination blockdiagram and schematic circuit diagram of an illustrative form of atelevision reproducing system embodying the present invention.

Reference now will be made to the drawing for a more detatileddescription of this embodiment of the invention. The system includes acomposite television signal receiver 1 which may be entirelyconventional. It will be understood that this apparatus may include oneor more stages of radio frequency signal amplification, a first detectoror frequency converter, one or more stages of intermediate frequencysignal amplification and a second or signal detector. Accordingly, itwill be understood that there is derived from the output circuits of thereceiver demodulated video and synchronizing signal intelligence.

The video signals derived from the receiver 1 may be in any one of anumber of different forms depending operation to be employed inoperating the image reproducing kinescope. This feature of the part ofthe present invention and, accordingly, there is not shown in detail thespecific means used for deriving the video signals in any particularform. It will be assumed, however, that the present invention isembodied in a color television system operating according to the dot orelemental multiplex principle. Such a system is described in greaterdetail in an article titled A sixmegacycle compatible high-definitioncolor television system" published by RCA Laboratories Division in theRCA Review, December l949-vol. X, No. 4, p. 504. A representative systemof this character also is described in a copending US. application ofJohn Evans, Serial No. 111,384 filed August 20, 1949 and titled ColorTelevision," now Patent No. 2,810,781,.irsued October 22, 1957. Inaccordance with a system of the type described in the publication and inthe Evans application referred to, the video signals are in the form oftime-spaced pulses representative respectively of the difierent colorcomponents of successive elemental area of the image to be reproduced.Accordingly, it will be understood that the pulses indicated at 2represent for example the blue, green and red color components ofsuccessive elemental areas of the image to be reproduced. These impulsesare amplified in a video signal channel 3 and thence they are impressedupon the intensity control electrode system of an electron gun 4 formingpart of a multicolor kinescope 5.

The kinescope also is provided with a luminescent screen 6 formed of amultiplicity of horizontal phosphor strips such as the red, green andblue light-producing strips 7, 8 and 9, respectively. In accordance withthe present invention, the screen 6 also includes a plurality ofconducting strips such as 10 which may be imbedded between, butelectrically insulated from, predetermined ones of the phosphor strips.These conducting strips serve as beam position-indicating strips or,more simply stated, indexing stripes. In the present case, it is assumedthat the conductors 10 are placed between the red and green phosphorstrips of each of the multiplicity of phosphor strip groups. Theconductors 10 are electrically connected together to form a grid whichis connected to an external circuit to be described more in detailsubsequently.

A second anode in the form of a metallic wall coating 11 is anotherconventional kinescope electrode which, as customary, is connected to asource of relatively high positive potential. The kinescope 4 also isprovided with a conventional deflection yoke 12 which may be energizedin the usual manner to deflect the electron beam both horizontally andvertically in accordance with a predetermined pattern to scan a rasterat the screen 6. Additionally, the kinescope is provided with anauxiliary deflection system which, in the present instance, isillustrated as a pair of plates 13. These electrodes are energized in amanner to be described to cause the electron beam to be deflectedvertically with a relatively high frequency while it is being deflectedhorizontally to scan successive lines of the desired raster.

The synchronizing signal intelligence derived from the compositetelevision signal receiver 1 is segregated from the video signals bymeans of a synchronizing signal separator 14 coupled to the output ofthe receiver. This apparatus also may be entirely conventional.Accordingly, it will be understood that there is derived from thesynchronizing signal separator both the horizontal and verticalsynchronizing pulses. The horizontal synchronizing pulses are impressedupon a conventional horizontal deflection wave generator 15. The outputof this generator is connected to the deflection yoke 12 as indicated toenergize it by a substantially sawtooth wave at line fre quency in theusual manner.

Suitable color synchronizing pulses are impressed upon a colordeflection wave generator 16 so as to synchronize its operation. Thisgenerator also may be of the type capable of producing a substantiallysawtooth wave at the color repetition frequency and at a fixed phaserelationship to the color component of the video signal. In the assumedcase of a system operating in accordance with the dot multiplexprinciple, the frequency of the wave produced by the generator 16 willbe of the order of 3.6 mc. per second. The output circuit of thisgenerator in which the sawtooth wave is produced is coupled to theauxiliary deflection plates 13. In this manner the electron beam isgiven an auxiliary sawtooth deflection of relatively small amplitude sothat, as it is being deflected by the yoke 12 to scan successivehorizontal lines in the usual manner, it traces a substantially sawtoothpath as indicated at 17. It is seen that the trace 17 extends only overone group of phosphor strips.

Further details of the synchronization of the color deflection wavegenerator 16 may be found in two publicaions by Radio Corporation ofAmerica titled Synchronization for Color Dot Interlace in the RCA ColorTelevision System, October 1949 and Recent Developments in ColorSynchronization in the RCA Color Television System, February 1950. Thesecolor synchronizing systems from the subject matter of copending US.patent applications of Randall C. Ballard, Serial No. 117,528 filedSeptember 24, 1949 and titled Systems of Color Television," now PatentNo. 2,678,348, issued May 1], 1954 and of Alda V. Bedford, Serial No.143,800, filed February ll, 1950 and titled Synchronizing Apparatus,"now Patent No. 2,728,812, issued December 27, 1955.

There also is derived from the color deflection wave generator 16 is aseries of pulses such as indicated at 18. These pulses occur at thecolor repetition rate and are of a fixed predetermined amplitude.Preferably this amplitude should be greater than the greatest possibleamplitude of the video signal pulses 2. The pulses 18 are impressed uponthe video signal channel 3 for mixing with the video signal pulses 2 insuch a manner that they may be employed as position reference signals.The phase of the pulses 18 should be adjusted relative to the videosignal pulses 2 so that, when mixed together, there is produced in theoutput circuit video channel 3 strain of pulses such as indicated at 19.It is seen that the position reference pulses 18 are mixed with thevideo signal pulses in such a way that they occur successively betweenthe green and red representative video signal pulses. By means of theposition reference pulses, the intensity of the electron beam iscontrolled independently of the video signal for a purpose to bedescribed in conjunction with the utilization of the signals produced bythe conductor grid of the kinescope screen.

The vertical synchronizing signals derived from the synchronizing signalseparator 14 are impressed by a coupling including a capacitor 21 and aresistor 22 upon a vertical deflection wave generator 23 for the purposeof synchronizing it. This generator also may be entirely conventional.The essential components of it are illustrated in detail in order toillustrate the manner in which the present invention functions inconjunction with it. The vertical deflection wave generator includes acombincd oscillator and discharge tube 24 and an output tube 25. Both ofthese tubes have been illustrated as triodcs for the purpose ofsimplicity. It will be understood that other types of tubes may be usedalternatively without departing from the present invention. In orderthat the tube 24 may function as a blocking type oscillator, feedbackmay be provided by inductively coupled anode and grid coils 26 and 27,respectively. The output circuit of the tube 24 also includes acapacitor 28 and resistors 29 and 3|] connected in series therewithbetween the anode circuit of the tube 24 and ground. The anode circuitof this tube also is connected through a resistor 31 to a source ofenergy of positive polarity.

The tube 24 normally is non-conducting so that the capacitor 28 chargesat a relatively slow rate through resistors 29, 30 and 31. When the tube24 is rendered conducting under the control of one of the verticalsynchronizing signals impressed upon the grid, the condenser 28 isdischarged at a relatively rapid rate through the tube 24. Accordingly,at the high potential terminal of the capacitor 28, there is developed asubstantially sawtooth wave as a result of the described operation.

The high potential terminal of the capacitor 28 is coupled by acapacitor 32 and a leak resistor 33 to the control grid of the outputtube 25. The anode of this tube is connected through the primary winding34 of an output transformer 35 to an energy source of positive polarity.The secondary winding 36 of this transformer is connected for thedeflection yoke 12 so as to provide it with a substantial sawtooth waveat the field deflection frequency.

The vertical deflection generator in actual practice may include otherfeatures such as potentiometers for controlling linearity and thevertical height of the raster scanned. However, since none of thesefeatures have any connection with the present invention they have notbeen specifically illustrated.

The vertical sawtooth deflection wave derived from the generator 23 ismade subiect to control in amplitude by means of apparatus in accordancewith a feature of the present invention. The grid formed by theconductors 10 of the screen 6 is connected to an output resistor 37externally of the kinescope 5. The output resistor also is connected, asindicated, to the source of potential for the second anode 11 in orderto minimize the potential difference between the grid conductors and thephosphor screen. The output resistor 37 also is bypassed to ground by acapacitor 38. The grid-connected terminal of the resistor 37, in thepresent form of the invention, is coupled by a capacitor 39 to an inputresistor 41 for an amplitude limiter 42. The limiter may be conventionalin form comprising, for example, an electron amplifier tube biased so asto be driven to saturation by the signals developed in the resistor 41.

The output circuit of the limiter 42 is connected to a resistor 43forming part of a signal combining circuit. Another resistor 44connected in series with the resistor 43 forms another component of thesignal combining circuit and has its terminals connected to the sawtoothwave output terminals of the color deflection wave generator 16. The tworesistors 43 and 44 are further connected to a series arrangement of adiode 45, a diode load circuit, including a resistor 46 and a shuntingcapacitor 47,

and a source of biasing voltage represented by the battery 48.

The sawtooth wave 49 developed by the generator 16 at the colorrepetition frequency'isimpressed upon the deflection plates 13 to causethe beam to be deflected vertically along the trace 17 in the manerdescribed. In addition, the sawtooth wave 49 also is impressed upon thesignal combining resistor 44. [Position] Beam position indicatingsignals such as represented at 50 are derived, in negative polarity,from the grid of conductors in response to each traversal of theelectron beam over one of the conductors during the relatively slowportions of the sawtooth trace 17. Thae pulses, after being reversed inpolarity and limited in amplitude to a predetermined common level by thelimiter 42, are developed across the signal combining resistor 43 insuch a way that they are impressed upon the diode 45 in conjunction withthe sawtooth wave 49.

There is impressed upon the diode 45, therefore, a composite wave havingsubstantially the form shown at 51. It is seen that the composite waveconsists of successive cycles of a substantially sawtooth wave 52.Superimproved on each one of these sawtooth waves is a pulse such as 53corresponding to one of the pulses 50. It is seen that, depending uponthe time of occurrence of the pulses 50 relative to the sawtooth wave49, the superimposed pulses such as 53 have dilferent peak amplitudesrelative to a point of reference. The peak amplitudes of the the pulsessuch as 53 is an indication of the registration of the electron beamwith the luminescent screen 6.

For example, if it be assumed that the pulse 53 reprecauses thehorizontal sweep of the beam to move upward relative to the group ofphosphor strips efl'ects the traversal of one of the conductive strips10 at a time earlier than normal. Accordingly, such a signal pulsederived from the grid of conductors 10 would be represented at 54 whensuperimposed upon the sawtooth wave 52. Since the pulse 54 occursearlier than it should, it is placed upon a lower amplitude portion ofthe sawtooth wave and, therefore, has a smaller peak amplitude than anormal pulse 53, for example. Similarly, a downward deflection should.Such a pulse is represented at 55 with reference to the sawtooth wave52. It is seen that its peak amplitude is greater than that of thenormal pulse 53.

Diode 45 function as a peak rectifier, because the time constant of thediode load circuit, including resistor 46 and capacitor 47, is longcompared with the period of the composite waveform 51 impressed upon theanode. Accordingly, there is developed in the diode load circuit aunidirectional voltage which is approximately equal to the peak voltage,such as represented by the pulses 53,

tube 58 is provided by bias source 48.

Space current for the tube 58 is derived by a connection of the anode tothe resistor 31. It is seen that the voltage developed at the anode ofthe tube 58 is controlled by the magnitude of the space currentconduction in this tube. This, in turn, is responsive to theregistration signals such as represented by the pulses 53, 54 and 55 inthe maner described. The voltage developed at the anode of the tube 58is that which is impressed upon the capacitor 28 for charging it asdescribed. A variation of the voltage correspondingly varies thecharging rate of this capacitor whereby to control the verticaldeflection of the electron beam in the manner desired.

Thus, a decrease in the anode voltage of the tube 58 in response to anincrease in the current conduction therein efi'ects a decrease in therate at which the capacitor 28 is charged. Accordingly, the sawtoothwave derived from the generator 23 will be altered suitably so that theelectron beam will be deflected vertically at a slower rate. Similarly,an increase in the vertical deflection of the electron beam is effectedby increasing the rate at which the capacitor 28 is charged by means ofan increase in the anode voltage of the tube 58 in response to adecrease in the current conduction therein.

It may be found in some cases that it is unnecessary to provide theconductors 10 in such form that they extend horizontally throughout theentire screen 6. It is considered ll) be within the scope of the presentinvention to provide a structure in which the conductors 10 are of asomewhat shorter nature. It may be found t at it is not necessary to theconductors regions so that they may be traversed by the scanning beamslightly in advance of the scansion of the screen for imagereproduction. In such a case, the beam may be modulated in a desiredmaner prior to the modulation thereof by the video signals representingthe different color components of the image to be reproduced. Theposition of the scanning beam relative to any group of phosphor stripsthen would be indicated prior to the start of the scansion of this groupof strips. In such a case, the vertical deflection wave generaator mustbe sufliciently stable in operation to maintain good linearity for theduration of each horizontal line scansion.

In cases where it is found to be unnecessary to extend the conductors 10throughout the entire length of each group of phosphor strips, it willnot be necessary to include the position reference pulses such as 18with the video signal pulses as described in connection with theillustrative embodiment of the invention shown herein. Furthermore, itmay be determined, in some cases where the conductors 10 do extend theentire width of the screen, that the special position reference pulses18 are not needed for the successful operation of the system.

that they are separated slightly from one another. Such an arrangementwill minimize an undesired mixing of the colors which might otherwise beproduced.

Also, it will be apparent that the diode 45, in conjunction with itsassociated circuit components, functions essentially as a phasecomparator in detecting any phase diflerences between the colordeflection wave and the gridgenerated position indicating pulses.Accordingly, it will be understood that equivalent types of phasecomparators may be used instead of that disclosed without departing fromthis invention.

that there is provided an improved color television image reproducingsystem. The color selection is achieved in a particularly advantageousmanner by the comparatively simple expedient of giving the electron beama small amplitude, auxiliary vertical deflection while it is beingdeflected conventionally both horizontally and vertically so that itsuccessively and repeatedly traverses difl'erent phosphor strips of agroup capable respectively of producing light of the different componentimage colors in response to and concurrently with the reception of videosignals representative of these component image colors.

Furthermore the invention provides a relatively simple and efficientmeans for maintaining the necessary registration of the electron beamwith successive groups of a multiplicity of groups of horizontalphosphor strips.

The nature of the present invention is substantially as described in theforegoing specification. Its scope is set forth in the following claims.

What is claimed is.

1. In a color television system, a multi-color kinescope having aluminescent screen including a multiplicity of groups of phosphor stripscapable respectively of producing light of a plurality of componentimage colors in response to excitation by an electron beam, said screenalso having conductors aligned respectively with said groups of phosphorstrips and connected together electrically to form a grid, means fordeveloping an electron beam and deflecting it to scan a raster at saidscreen, means including a periodic wave generator for effecting anauxiliary deflection of said beam in a predetermined cyclicallyrecurring pattern in a direction transverse to the direction of saidphosphor strips, whereby successively and repeatedly to traverse saidphosphor strips, thereby producing difl'erently coloredimage-representative light and also to traverse said grid conductors,thereby developing position-indicating pulses, means for combining saidposition-indicating pulses with said periodic auxiliary deflection waveto develop a control signal representative of any misregistration ofsaid beam with said screen, and means responsive to said control signaland coupled to said beam-deflecting means to correct the deflection ofsaid beam in the direction transverse to the direction of said phosphorstrips.

2. In a color television system, apparatus as defined in claim 1wherein, said combining means includes a. circuit upon which areconcurrently impressed said periodic auxiliary deflection wave and saidposition-indicating pulses whereby said pulses are superimposed uponsaid wave to form said developed control signal, and means forconverting the peak amplitudes of said control signal into aunidirectional control voltage for impression upon said beam-deflectingmeans- 3. In a color television system, apparatus as defined in claim 2wherein, said converting means includes a diode biased so as to berendered conducting only in response to said peak amplitudes whereby todevelop a series of time-spaced pulses, and a filter coupled to theoutput circuit of said diode to produce said unidirectional controlvoltage from said series of pulses.

4. In a color television system, apparatus as defined in claim 3wherein, said beam-deflecting correcting means includes an electron tuberesponsive to said unidirectional control voltage to variably controlthe rate of said beam deflection in said transverse direction.

5. In an image reproducing system, a cathode ray tube having aluminescent screen, a plurality of spaced conducting strips extendinghorizontally across said screen and connected together to form a grid,means for developing an electron beam and deflecting it horizontally andvertically to scan a raster at said screen, means for efiecting anauxiliary sawtooth vertical deflection of said beam whereby torepeatedly traverse each of said strips and consequently develop pulsesindicative of the linearity of said vertical beam deflection, meansresponsive to said developed pulses for generating control signalshaving amplitudes varying in accordance with the time in said auxiliarysawtooth beam deflection cycles at which said pulses are developed, andmeans responsive to said control signals to maintain the linearity ofsaid vertical beam deflection sumciently accurate to cause said beam toscan said screen in substantially precise horizontal lines.

6. In a color television receiver, the combination ineluding: amultl-color klnescope having a luminescent screen including amultiplicity of groups of phosphor strips capable respectively ofproducing light of a plurality of component image colors in response toexcitation by an electron beam, said screen also having beamposilion-indicating strips aligned respectively with said groups ofphosphor strips and capable of developing beam posilion-indicatingsignals in response to excitation by an electron beam; means fordeveloping an electron beam and deflecting it to scan a raster at saidscreen; means for efiectlng an auxiliary deflection of said beam in apredetermined cyclically recurring pauern in a direction transverse tothe direction of said phosphor strips, whereby successively andrepeatedly to impinge upon said phorphor strips, thereby producingdifierently colored imagerepresentative light, and also to impinge uponsaid beam position-indicating strips, thereby developing beamposilion-indicating signals; and means responsive to said beamposition-indicating signals to control the rate of said raster-scanningbeam deflection in a direction transverse to said screen strips.

7. In a color television receiver, the combination including: amultl-color kinescope having a luminescent screen including amultiplicity of groups of phosphor strips capable respectively ofproducing light of a plurahry of component image colors in response toimpingemen: by an electron beam, said screen also having beam positionindicating strips aligned respectively with said groups of phosphorstrips and capable of developing beam position-indicating signals inresponse to impingement by an electron beam; means for developing anelectron beam and deflecting it to scan a meter at said screen; meansfor efiecting an auxiliary deflection of said beam in a predeterminedcyclically recurring pattern in a direction transverse to the directionof said phosphor strips, whereby successively and repeatedly to impingeupon said phosphor strips, thereby producing diflerently coloredimagerepresentatlve light, and also to impinge upon said beamposition-indicating strips, thereby developing beam post'-Iion-indicating signals; means responsive to video signalsrepresentative of said component image colors to modulate the intensityof said electron beam substantially concurrently with the impingement ofsaid beam upon said phosphor screen strips; means responsive tosubstantially uniform amplitude reference signals occurring at saidauxiliary beam deflection rate to modulate the intensity of said beamsubstantially concurrently with the impingement of said beam upon saidbeam position-indicating screen strips; and means repsonsive to saidbeam position-indicating signals to control the rate of saidraster-scanning beam deflection in a direction transverse to said screenstrips.

8. In a color television receiver, the combination including: amulti-color lu'nescope having a luminescent screen including amultiplicity of groups of phosphor strips capable respectively ofproducing light of a pluraliry of component image colors in response toimpingement by an electron beam, said screen also havingbeamporition-indicating strips aligned respectively with said groups ofphosphor strips and capable of developing beam position-indicatingsignals in response to impingement by an electron beam; means fordeveloping an electron beam and deflecting it to scan a raster at saidscreen,- means for efiecting an auxiliary deflection of said beam in aprederermined cyclically recurring pattern in a direction transverse tothe direction of said phosphor strips, whereby successively andrepeatedly to impinge upon said phosphor strips, thereby producingdlfierently colored imagerepresenmtlve light, and also to impinge uponsaid beam position-indicating strips, thereby developing beamposilion-indicating .n'gnolr; means responsive to video signals varyingin amplitude in accordance with said component image colors to modulatecorrespondingly the intensity of said electrom beam substantiallyconcurrently with the impingement of sold beam upon sold phosphor screenstrips: means responsive to reference signals having a substantiallyuniform amplitude greater than the greatest amplitude of sold videosignals and occurring at said auxillary beam deflection rate to modulatecorrespondingly the intensity of said beam substantially concurrentlywith the impingement of said beam upon said beam position-indicatingscreen strips; and means responsive to said beam position-indicatingsignals to control the rate of said raster-scanning beam deflection in adirection transverse to said screen strips.

9. In a cathode ray tube display system: means for producing a signalcomprising successive portions representative of difierent intelligencecomponents, portions representative of particular components occurringin a predetermined order and recurring at a predetermined rate; acathode ray tube for reproducing the intelligence represented by saidsignal, said tube comprising a source of an electron beam, and afluorescent screen comprising a plurality of substantially parallellydisposed phosphor strips; means [or deflecting said beam in a directiongenerally parallel to said phosphor strips and at a rate such as tocause said beam to traverse only a portion of the length of a givenstrip during one cycle of said signals; means for deflecting said beamin a direction generally transverse to said phosphor strips at a ratesuch as to cause said beam to traverse diflerent strips duringsuccessive scans in said direction generally parallel to said strips;means for producing recurring auxliliary deflection of said electronbeam in said direction generally transverse to said phosphor strips at arate substantially equal to the rate of recurrence of said portions ofsaid signal and of an amplitude sufiicient to cause said beam totraverse substantially the width of a phosphor strip during each cycleof said deflection; means responsive to electron beam impingement on apredetermined region extending longitudinally of each said strip toproduce a signal indicative of said impingement; and means forultillzing said produced signal to control the instantaneous rate ofdeflection of said beam in said direction generally transverse to saidphosphor strips. 10. In a cathode ray tube display system: means forproducing a signal comprising successive portions representative ofdiflerent intelligence components, portions representative of particularcomponents occurring in a predetermined order and recurring at apredetermined rate; a cathode ray tube for reproducing the intelligencerepresented by said signal, said tube comprising a source of an electronbeam, a fluorescent screen comprising a plurality of substantiallyparallelly disposed phosphor strips and a plurality of indexing stripes,each associated with one of said phosphor strips and disposedsubstantially parallel thereto; means for deflecting said electron beamin a direction generally parallel to said phosphor strips and an ratesuch as to cause said beam to traverse only a portion of the length of agiven strip during one cycle of said signal; means for deflecting saidelectron beam in a direction generally transverse to said phosphorstrips at a rate such as to cause said beam to traverse different stripsduring successive scans in said direction generally parallel to saidstrips; means for producing recurrent auxiliary deflection of saidelectron beam in said direction generally transverse to said phosphorstrips at a rate substantially equal to the rate of recurrence of saidportions of said signal and of an amplitude suflicient to cause saidbeam to traverse substantially the width of a phosphor strip and totraverse the indexing stripe associated with a strip during each cycleof said deflection; means for deriving a signal in response toimpingement of said electron beam on said indexing stripes; and meansfor utilizing said derived signal to control the instantaneous rate ofdeflection of said beam in said direction generally transverse to saidphosphor strips.

II. In a cathode ray tube display system: means for producing a signalcomprising successive portions repreresentative of diflerentintelligence components occurring in a predetermined order and recurringat a predetermined rate; a cathode ray tube for producing visibleindications of the intelligence represented by said signal, said tubecomprising a screen and means for projecting an electron beam towardsaid screen; means for deflecting said beam in first and seconddiflerent directions across said screen and at rates such as to tracesuccessively a plurality of substantially parallel paths upon saidscreen; a plurality of phosphor strips, each disposed longitudinally ofone of said beam paths upon said screen; a plurality of indexingstripes, each associated with one of said phosphor stripes and disposedsubstantially parallel thereto; means for producing cyclical deflectionof said beam across said screen in said first direction at a ratesubstantially equal to said rate of recurrence of particular portions ofsaid signal and of an amplitude suflicient to cause said beam totraverse the width of a phosphor strip and the indexing stripeassociated with said strip during each cycle of said deflection; meansfor deriving a signal in response to impingement of said beam on saidindexing stripes; and means for utilizing said derived signal to controlthe rate of beam deflection in said first direction.

12. In a cathode ray tube display system, means for producing a signalcomprising successive portions representative of difierent intelligencecomponents occurring in a predetermined order and recurring at apredetermined rate; a cathode ray tube for producing visible indicationsof the intelligence represented by said signal, said tube comprising ascreen and means for projecting an electron beam toward said screen;means for deflecting said beam in first and second mutuallyperpendicular directions across said screen and at rates such as totrace successively a plurality of substantially parallel paths upon saidscreen; a plurality of phosphor strips, each disposed longitudinally ofone of said beam paths upon said screen; a plurality of indexingstripes, each associated with one of said phosphor stripes and disposedsubstantially parallel thereto; means for producing cyclical deflectionof said beam across said screen in said first direction at a ratesubstantially equal to said rate of recurrence of particular portions ofsaid signal and of an amplitude suflicient to cause said beam totraverse the width of a phosphor strip and the indexing stripeassociated with said strip during each cycle of said deflection; meansfor deriving a signal in response to impingement of said beam on saidindexing stripes; and means for utilizing said derived signal to controlthe rate of beam deflection in said first directio 13. In a cathode raytube display system: means for producing a signal having successiveportions representative of difierent intelligence components occurringin a predetermined order and recurring at a predetermined rate; acathode ray tube for producing visible indications of the intelligencerepresented by said signal, said tube comprising a screen, means forprojecting an electron beam toward said screen, and means responsive tosaid signal to control the intensity of said beam, said screen having aplurality of substantially parallel phosphor strips and a plurality ofindexing stripes, each associated with one of said strips and disposedsubstantially parallel thereto; means for producing successivedeflections of said beam longitudinally of diflerent ones of saidphosphor strips at such a rate as to cause said beam to traverse only afraction of the length of a particular strip during one cycle of saidsignal; means for producing cyclically recurrent deflections of saidbeam transversely of said phosphor strips at a rate substantially equalto the said rate of recurrence of signal portions and of an amplitudesuflicient to cause said beam to traverse the width of a phosphor stripand its associated indexing stripe during each cycle of said tranversedeflections; means for deriving a signal in response to impingement ofsaid electron beam on said indexing stripes; and means for utilizingsaid derived signal to control the deflection of said beam transverselyof said phosphor strips.

14. In a cathode ray tube display system: means for rate; a cathode raytube for producing visible indications of the intelligence representedby said signal, said tube comprising a screen, means for projecting anelectron beam toward said screen, and means responsive to saidintelligence signal to control the intensity of said beam, said screenhaving a plurality of substantially parallel phosphor strips and aplurality of indexing stripes, each associated with one of said stripsand disposed substantially parallel thereto; means for producingsuccessive deflections of said beam longitudinally of diflerent ones ofsaid phosphor strips at such a rate as to cause said beam to traverseonly a fraction of the length of a particular strip during one cycle ofsaid signal; means for producing cyclically recurrent deflections ofsaid beam transversely of said phosphor strips at a rate substantiallyequal to the said rate of recurrence of signal portions and of anamplitude sufficient to cause said beam to traverse the width of aphosphor strip and its associated indexing stripe during each cycle ofsaid transverse deflection; means for deriving a signal in response toimpingement of said electron beam on said indexing stripes; meansresponsive to variations in the times of occurrence of the said derivedsignal to produce a control signal; and means for utilizing said control'gnal to control the deflection of said beam transversely of saidphosphor strips.

15. In a cathode ray tube display system: means for producing a firstsignal having successive portions representative of diflerentintelligence components occurring in a predetermined order and recurringat a predetermined rate; a source of a second signal whose phase andfrequency are respectively indicative of the times of occurrence and therate of recurrence of the said intelligence representative portions ofsaid first signal; a cathode ray tube for producing visible indicationsof the intelligence represented by said first signal, said tubecomprising a screen, means for projecting an electron beam toward saidscreen, and means responsive to said signal to control the intensity ofsaid beam, said screen having a plurality of substantially parallelphosphor strips and a plurality of indexing stripes, each associatedwith one of said strips and disposed substantially parallel thereto;means for producing successive deflections of said beam longitudinallyof diflerent ones of said phosphor strips at such a rate as to causesaid beam to traverse only a fraction of the length of a particularstrip during one cycle of said first signal; means for producingcyclically recurrent deflections of said beam transversely of saidphosphor strips at a rate substantially equal to the said rate ofrecurrence of signal portions and of an amplitude suiflcient to causesaid beam to traverse the width of a phosphor strip and its associatedindexing stripe during each cycle of said transverse deflections; meansfor deriving a signal in response to impingement of said electron beamon said indexing stripes; means supplied with said second signal andwith said derived signal and responsive to relative phase variationstherebetween to produce a control signal proportional to saidvariations; and means for utilizing said control signal to control thedeflection of said beam transversely of said phosphor strips.

16. In a cathode ray tube display system: means for producing a signalhaving successive portions representative of intelligence respectingdifierent color components occurring in a predetermined order andrecurring at a predetermined rate; a cathode ray tube for producingvisible indications of said color components, said tube comprising ascreen, means for protecting an electron beam toward said screen, andmeans responsive to said intelligence signal to control the intensity ofsaid beam,

said screen including a plurality of substantially parallelly disposedgroups of phosphor stripes, each of said groups including diflerentstripes responsive to electron beam impingement to produce light of saiddiflerent colors, difierent color stripes being disposed in the sameorder within each said group in which the said successive signalportions are representative of difierent color components, and aplurality of indexing stripes, each associated with one of said groupsof phosphor stripes and disposed substantially parallel thereto; meansfor producing successive deflections of said beam longitudinally ofdiflerent ones of said phosphor stripe groups at such a rate as to causesaid beam to traverse only a portion of the length of a particular groupduring one cycle of said signal; means for producing cyclicallyrecurrent deflections of said beam transversely of said phosphor stripegroups at a rate substantially equal to the said rate of recurrence ofsignal portions and of an amplitude sufi'icient to cause said beam totraverse all the phosphor stripes of a group and the indexing stripeassociated therewith during each cycle of said transverse deflections;means for deriving a signal in response to impingement of said electronbeam upon said indexing stripes; and means for utilizing said derivedsignal to control the deflection of said beam transversely of saidgroups.

17. In a cathode ray tube display system: means for producing a signalhaving successive portions representative of red, green and blue colorcomponents occurring in a predetermined order and recurring at apredetermined rate; a cathode ray tube for producing visible indicationsof said intelligence, said tube comprising a screen, means forprojecting an electron beam toward said screen and means responsive tosaid intelligence signal to modulate the intensity of said beam, saidscreen including a plurality of substantially parallelly disposed groupsof phosphor stripes, each group comprising a red, a green and a bluelight emissive stripe arranged in the some order as the said order ofoccurrence of color representative signal portions, and a plurality ofindexing stripes, each associated with one of said groups of phosphorstripes and disposed substantially parallel thereto; means for producingsuccessive deflections of said beam across said screen longitudinally ofdifierent ones of said phosphor stripe groups; means for producingcyclically recurrent deflections of said beam transversely of saidgroups at a rate substantially equal to the said rate of recurrence ofsignal portions, of amplitude such as to traverse a red, a green andblue light emissive phosphor stripe and an indexing stripe during eachcycle of said lastnarned deflections, and in such sense as to traversesaid stripes in the order in which the said signal portions arerepresentative of difierent color components; means for deriving asignal in response to impingement of said electron beam on said indexingstripes; and means for utilizing said derived signal to control thedeflection of said beam transversely of said phosphor stripes.

References Cited by the Examiner The following references, cited by theExaminer, are of record in the patented file of this patent or theoriginal patent.

UNITED STATES PATENTS 2,415,059 1/47 Zworykin 178-54 2,490,812 12/49Hufimann 178-54 2,530,431 11/50 Hufimann 178-54 2,545,325 3/51 Welmer1785.4 2,671,129 3/54 Moore l78-5.4

DAVID G. REDmitAUGI-L Primary Examiner. NEWTON N. LOVEWELL, Examiner.

